So how is it, that after more than two years of writing this blog, I've yet to mention what is perhaps the most infamous of plant types - the carnivorous plant? Well, I'll delay no longer and share some images of Nepenthes densiflora, which can also be referred to as pitcher plants or monkey cups.
To be utterly specific, the term pitcher plant refers to two different families of carnivorous plants: Nepenthaceae, which are old world vining plants and Sarraceniaceae, which are terrestrial new world pitcher plants. Nepenthes is the only genera in its family, whereas three genera exist in the Sarraceniaceae family.
Nepenthes leaves initially look quite ordinary, but soon a tendril forms at the tip which eventually becomes a pitcher or cup. The "lid" that forms above the pitcher is not to keep insects from escaping but instead is to protect the cup as it develops. When the pitcher is finally ready to capture its prey the lid opens more fully.
When the cup gets larger, it begins to inflate with air and consequently it collects liquid. The plant begins to emit an odor of nectar to entice insects. The insect enters the pitcher - perhaps alighting on the toothed peristome (rolled leaf) at the top of the cup. When it tries to walk on the peristome, the surface essentially flakes away, causing it to slip down the sides of the pitcher and into the liquid. As the insect struggles to escape, the movement triggers plant glands to emit digestive acids which can render a midge fly to a mere memory in hours. The largest of the pitchers, Nepenthes rajah can even digest mice!
Nepenthes is not the only beneficiary of the prey it traps. Over 150 species have adapted to survive the diabolical morphology of the pitcher plant. Mosquito larvae live in the pitcher and find sustenance in the decaying remains of insects and some species of Nepenthes even have developed "pockets" in their stems to provide habitat for ants. The ants crawl into the pitcher to help themselves to a freshly-trapped fly, bring the fly to the peristome and dismember it. Smaller pieces of the fly fall back into the phytotelma (a water body formed by a plant) and are digested. Crab spiders and frogs have also learned to benefit from some species of Nepenthes. However, that doesn't include Nepenthes rajah - which can make a diet out of frogs quite easily.
Nepenthes densiflora is native to the Sumatran highlands and thrives best in elevations of 8000 feet or more. The genus name is compliments of Linnaeus himself. It's assumed by most that he was referring to the mythological elixir Nepenthe which is referenced in Homer's Odyssey.